1

85" MXS 50cc ARF Assembly Manual

Copyright 2020 Extreme Flight RC

2

Congratulations on your purchase of the Extreme Flight RC 85" MXS ARF! Purpose built for the multitude of 50-60cc engines on the market, this brand new airframe is the perfect complement to these venerable power plants that have been neglected for far too long. Our design team started with a very specific goal with careful consideration of weight, wing area and performance parameters to make sure we delivered the ultimate light weight 50cc performance machine. We are happy to report that our lofty goals for this airframe were not only met but exceeded!

The ultimate low and slow 3D machine, the 85" MXS also excels in XA and precision flight regimes. With reduced control surface throws the MXS

is a big pussycat and makes a great sport flyer. Crank up the rates and prepare to be amazed by the truly unlimited potential of this airframe!

The 85" MXS is loaded with features including advanced use of composites for a super strong, rigid, yet light weight airframe, carbon fiber wing spars, main gear, tailwheel assembly, wing and stab tubes. It features a 2 piece removable wing and stab with new quick release mechanisms to allow speedy setup and break down at the flying field. The MXS is available in 2 high visibility Oracover color schemes with high contrast bottom colors and a pro quality hardware package including genuine Dubro ball links. Elevators and ailerons are pre-hinged and hinge lines are sealed with Oracover, facilitating a quick assembly. Experienced modelers should be able to finish assembly in a couple evenings of relaxed shop time.

3

Please take a few moments to read this instruction manual before beginning assembly. We have outlined a fast, clear and easy method to assemble this aircraft and familiarizing yourself with this process will aid in a quick, easy build.

Please read the following paragraph before beginning assembly of your aircraft!

THIS IS NOT A TOY! Serious injury, destruction of property, or even death may result from the misuse of this product. Extreme Flight RC is providing you, the consumer with a very high quality model aircraft component kit, from which you, the consumer, will assemble a flying model. It is beyond our control to monitor the finished aircraft you produce. Extreme Flight RC will in no way accept or assume responsibility or liability for damages resulting from the use of this user assembled product. This aircraft should be flown in accordance to the AMA safety code. It is highly recommended that you join the Academy of Model Aeronautics in order to be properly insured, and to operate your model at AMA sanctioned flying fields only. If you are not willing to accept ALL liability for the use of this product, please return it to the place of purchase immediately.

Extreme Flight RC, Ltd. guarantees this kit to be free of defects in materials and workmanship for a period of 30 DAYS from the date of purchase. All warranty claims must be accompanied by the original dated receipt. This warranty is extended to the original purchaser of the aircraft kit only. Extreme Flight RC in no way warranties its aircraft against flutter. We have put these aircraft through the most grueling flight tests imaginable and have not experienced any control surface flutter. Proper servo selection and linkage set-up is absolutely essential. Inadequate servos or improper linkage set up may result in flutter and possibly the complete destruction of your aircraft. If you are not experienced in this type of linkage set-up or have questions regarding servo choices, please contact us at info@extremeflightrc.com or 770-887-1794. It is your responsibility to ensure the airworthiness of your model.

4

A few tips to ensure success 1. We are very pleased with the level of craftsmanship displayed by the builders in our factory. Through

hundreds of grueling test flights containing maneuvers that no aircraft should be subjected to, our prototypes have remained rigid and completely airworthy. Having said that, it is impossible for us to inspect every glue joint in the aircraft. Take a few minutes and apply some CA to high stress areas such as the aileron servo mounting trays , landing gear mount, anti rotation pins, wing and stab root ribs, etc.

2. Having survived the journey half way around the world while experiencing several climate changes, it is not uncommon for a few wrinkles to develop in the covering. Fear not! These are not manufacturing defects, and are easily removed with a little bit of heat. Use a sealing iron to go over all seams, stripes and sharp points in the covering scheme. You may want to apply a drop of clear fingernail polish at the tip of all sharp points to prevent them from lifting. To remove wrinkles use a 100% cotton tee- shirt or microfiber cloth and your heat gun and heat the covering while gently rubbing the covering onto the wood with the t-shirt or cloth. Be careful not to use too much heat as the covering may shrink too much and begin to lift at the edges. Take your time, and a beautiful, paint like finish is attainable.

3. By the time your aircraft arrives at your door step it will have been handled by a lot of people. Occasionally there are small dings or imperfections on some of the surfaces. An effective method to restore these imperfections to original condition is to use a very fine tipped hypodermic needle to inject a drop of water under the covering material and into the ding in the wood. Apply heat to the area with a sealing iron and the imperfection will disappear. Deeper marks may require that this process be repeated a couple of times to achieve the desired result, but you will be surprised at how well this technique works.

4. DO NOT SKIMP ON SERVOS! Your aircraft is equipped with very large control surfaces that deflect well over 45 degrees. A lot of servo power is required to prevent flutter and to maintain the required deflection for maneuvers. We absolutely recommend the use of METAL GEARED servos with a minimum of 400 oz. inches of torque.

5. Use a high quality epoxy for installing the composite control horns. We highly recommend the use of Pacer Z-Poxy 30 minute formula. We have used this glue for many years with zero failures.

6. You may want to add a bead of RC-56 Canopy glue to the intersection of the canopy/hatch and its wood frame for additional strength and resistance to vibration. DO NOT USE CA here as it will fog the canopy.

7. Your aircraft is built using very modern construction techniques and is very light weight for its size. As with any high performance machine, regular inspection and maintenance is a must. While disassembling your aircraft after a flying session, pay close attention and inspect glue joints, linkages and loose covering to be sure the airframe is sound. A few minutes spent doing this will help ensure airframe longevity.

8. Be sure to put a drop of blue Loctite thread lock on every bolt on this aircraft! Failure to do so may cost you your aircraft! This includes servo arm screws!

9. The basic assembly process of the Extra is very similar to that of our previously released 50cc and 100cc aircraft. Some of the photos in this manual may be taken from a previous aircraft release if we determined that the assembly step was illustrated more clearly in these photos.

If repairs become necessary the Ultracote colors used are as follows: White/Red/Black/Charcoal/Silver color scheme: True Red-#HANU866, White-# HANU870, Pearl

Charcoal-#HANU846, Silver-#HANU881, Black-#HANU874 Bright Yellow/Deep Blue/Silver/Midnight Blue/Cub Yellow color scheme: Cub Yellow-#HANU884

Midnight Blue- # HANU885, Silver-#HANU881, Bright Yellow-#HANU872, Deep Blue-#HANU873

5

Since the 85" MXS (and most of our other giant scale models) now come pre-hinged and the hinge gaps sealed, the most time consuming task of the assembly process has been eliminated. This leaves a very minimal amount of gluing for the assembler, which consists of installing the composite control horns in the ailerons, elevators and rudder, with only the rudder hinges needing to be glued. For this reason we recommend that you spend the first hour or so of assembly completing this task. After this has been completed the rest of the assembly process consists of installing components into and onto the airframe. 1. Locate the proper control horns and base plates for each flying surface. Place the 2 control horns into the baseplate and carefully insert them into the pre-cut slots in the control surface. Use a fine tipped felt marker to trace around the baseplate.

2. Remove the horn assembly and use your #11 blade to remove the covering from inside the ink line that you traced around the control horn base. Wipe away the ink line with a paper towel soaked in denatured alcohol.

6

3. Scuff the portion of the horns that will be inserted into the elevator with sandpaper.

4. Locate your epoxy, mixing cup, an old pushrod to stir with and a length of nylon cable tie to apply the epoxy. We have used Pacer 30 minute Z-poxy for over 2 decades with excellent results and zero bond failures and we highly recommend this product.

7

5. Mix a generous batch of epoxy being careful to use equal parts resin and hardener.

6. Use the nylon cable tie to apply epoxy to the slots and thoroughly coat the control horns on both sides of each horn.

8

7. Insert the control horns into the slots and ensure that the horns are properly seated against the base plate and the base plate is flush against the control surface.

9

8. Wipe away the excess epoxy with a paper towel soaked in denatured alcohol, making sure to do a good job of cleaning the area. Insert a 3mm bolt and ball link into position and confirm proper alignment before the epoxy sets.

10

9. Repeat this process for the other stab half, the aileron control horns and the rudder control horns. ***PLEASE NOTE*** pull-pull rudder actuation with the rudder servo mounted in the rudder tray under the canopy is recommended for lightweight 50cc engines in order to achieve proper balance. If using a heavier 60cc or electric motor setup with large 12S LiPo batteries the rudder servo may be mounted in the rear of the fuselage. This decision will determine whether you use a single control horn set for push-pull rudder actuation or a dual horn setup for pull-pull. Be sure to use the included plywood jig to make sure the rudder control horns are properly aligned while the epoxy sets.

11

12

10. Assemble and install the servo mounting grommets. Connect an EF 20 AWG servo extension to each aileron servo lead (secure with heat shrink tubing or an EF Servo Safety Clip) and install the elevator and aileron servos in their designated locations. We highly recommend using the Extreme Flight socket head servo screws to mount your servos. The servo output spline of the elevator and aileron servos should be oriented toward the front of the model. 11. Locate the linkage components from the hardware package and the recommended servo arms for each surface. Thread a ball link onto each end of the provided turnbuckle pushrods. Install the linkages for the elevators and ailerons as pictured using the provided 3mm fasteners. Be sure to use the small conical spacers between the aluminum servo arm and ball link to prevent binding. For the elevator use the 1.75" mounting hole on the 2" EF arm. For the ailerons use the 1.25" hole in the 1.5" EF arm. This will ensure maximum mechanical advantage and best servo resolution.

13

Fuselage Assembly 12. We’ll begin by installing the landing gear. Locate the carbon fiber main landing gear, 4-4mm bolts, lock nuts and washers. Insert the gear into the slot on the bottom of the fuselage and center it in the slot. Secure the landing gear with 4 4mm bolts, washers and nylon insert lock nuts by inserting the bolts and washers through the carbon gear and the aluminum gear mounts inside the fuselage. Secure with the 4mm nylon insert lock nuts.

14

13. The landing gear fairings add a nice scale touch to the aircraft. Slide the fairing onto the gear and up against the fuselage. Secure the fairing to the gear with "Goop" silicon glue. Use blue painters tape to secure the fairings until the adhesive sets.

14. Locate the 2 axles, 2 locking nuts, 2 wheels, 4 wheel collars, 2 outer pant supports and plywood spacers and 2 wheel pants from the hardware package. Place the threaded portion of the axle through the hole in the landing gear, place a washer onto the axle and secure the axle with a locking nut.

15

15. Use your rotary tool and a grinding bit or a file to create a flat spot on the axle for the wheel collar and wheel pant support set screws to seat against. Attach the aluminum axle support to the plywood spacer with the provided wood screws.

16. slide a wheel collar onto the axle followed by the wheel and then the wheel pant support. Push the wheel pant support as far as possible onto the axle and tighten the set screw, then adjust the wheel collar position to properly position the wheel on the axle as shown.

16

17. Slide the wheel pants into position and secure with 2 3mm bolts and washers inserted through the carbon gear and into the blind nuts in the wheel pants. Be sure to use thread lock on the bolts! Pull the pant back from the plywood support block and run a bead of Epoxy on the plywood surface to adhere the block to the wheel pant wall. This adds an enormous amount of strength and rigidity to the wheel pant.

17

18. Next let’s install the rudder onto the fuselage. Glue the hinges into the rudder first with epoxy and allow to cure. Use a pushrod to apply epoxy to the holes in the rudder post and push the rudder into position and wipe away any excess epoxy with a paper towel and denatured alcohol.

19. Drill a hole in the bottom of the rudder 3 inches back from the front of the bevel to accept the ball link for the tiller arm. Secure the ball link with epoxy. When dry slide the tiller arm into the hole in the ball link and secure the tailwheel assembly to the fuse with the provided 3mm bolts. Again, be sure to use blue thread lock on all bolts!

20. Next let’s install the engine. We have made this process very easy. If using a DA-50, DA-60, GP-61 or DLE-61 there are drill marks laser scribed on the face of the firewall (Please note, the DLE-61 mounting pattern is slightly different than the DLE-55). If using another engine or electric motor simply download a template from their website and tape it in place over the centering marks that have been laser scribed into the front of the firewall. Drill at the location of the mounting holes. For best results I always use a pointed reamer to accurately mark the center of the holes then start drilling with a 1/16" bit and continue with progressively larger bits until I achieve the correct hole diameter. This ensures that the hole is accurately drilled in the correct location and makes a much neater hole in the plywood.

18

19

21. The distance from the front face of the motor box to the motor drive washer is 172mm or 6.8 inches (this is the length of the DLE-61, the longest of the engines recommended). Because the DA-50 is the recommended motor we have included a set of machined aluminum standoffs to be used in conjunction with the stock 2.5" standoffs included with the DA-50 to achieve the proper spacing.

22. The following photos show the GP-61 and Xpwr 40 mounted on an 85" airframe. We used a Blazing Star DA-60 mount for the GP-61 (they share the same mounting pattern) and the full length Blazing Star XXL Standoff Set to achieve the proper spacing with the Xpwr 40. You may notice we used a hacksaw to remove 1" from the muffler downpipe to make fitting the cowl easier.

20

***Please note that we removed the laser scribed panels in the F1 former in our electric powered airframe to allow cooling air to reach the batteries***

23. There is a hole in the bottom of the motorbox to mount your throttle servo. This location corresponds to the throttle arm on most single cylinder engines provides a straight shot from the servo arm to the throttle arm. Some engine makes may require a different location. If using the DA-50 mount the servo in the provided location and fabricate the throttle linkage from the provided components.

21

24. If using an electric motor we recommend mounting the ESC to the bottom of the motorbox either with screws, nylon cable ties or Velcro straps.

25. If using a lightweight 50cc engine like the DA-50 mount your rudder servo in the servo tray under the canopy using the manufacturer supplied mounting hardware. For proper geometry use the Extreme Flight 3” pull-pull rudder arm with the cables crossed. Assemble the pull-pull cable linkage as shown by inserting the end of the pull-pull cable into one of the aluminum crimp tubes. Insert the cable through the hole in the brass fitting and back through the crimp tube. Loop the cable one more time through the crimp tube and pull it tight. Use a crimping tool or set of side cutters to carefully crimp the tube in multiple places, taking care not to cut through the crimp tube and cable. Repeat this for the other 3 cable ends and install onto the servo arm and control horns using the provided 3mm hardware.

22

23

26. If using a 60cc engine or large electric motor with high capacity LiPo batteries mount the rudder servo in the provided location in the rear of the fuselage with the output spline mounted toward the rear of the aircraft. You will need to mount your rudder linkage to the interior side of the servo arm for sufficient clearance as shown. A 1.5 inch servo arm will provide full rudder deflection with travel control turned up in your transmitter menu.

24

27. If you plan to keep your stabs attached to the fuselage during transport then a 36" 20 Awg servo extension is long enough. If you plan to remove the stabs you will need to use a 48" extension. Secure the extension to the elevator servo lead with an EF Servo Safety Clip or heat shrink tubing. 28. The 85" MXS uses a new quick mount system that allows the stab/elevator assembly to be installed or removed quickly with no tools required. The thumb screws ride on a sliding carriage system which when moved to the forward position allow the stabs to be slid into place. The bolts are then pushed rearward into position and tightened. The front thumbscrew has an O ring that fits into a recess in the forward mounting tab. This prevents the carriage from sliding forward when the thumbscrew is tightened. To remove simply loosen the rear thumb screw a couple turns to clear the tab. The forward thumbscrew will require a few more turns so that the O ring clears the forward tab.

25

29. If using a 50-60cc gas engine install a Flowmaster 17 ounce tank onto the tank tray and plumb with EF Flowmaster Blue Fuel Line. There is a laser cut opening to accept an EF Fuel Dot as well. The following picture shows the location of our tank, batteries and receiver which provided the ideal center of gravity.

30. Mount your ignition to the interior side of the motor box lid and secure the lid with 4 screws. Next use a rotary tool to cut the cowl to clear the cylinder head, mufflers and make an air exit. Take a minute to add some thick CA or Epoxy to the intersection of the cowl and plywood cowl ring.

26

31. There is a set of clear plastic baffles included to be used for electric setups to direct air over the motor. Cut and trim the baffles and glue to the cowl inlets with Goop or medium CA.

32. Secure the cowl to the fuselage by inserting a 3mm bolt through the bottom of the cowl and into the blind nut in the lower fuselage along with 2 3mm bolts inserted through the F1 former and into the blind nuts in the cowl. Use blue thread lock on all 3 bolts! The factory has included an assortment of rubber grommets that you can use to prevent your fuel line from getting chafed. You can see in this photo we used a couple of them for the fuel tubing and the throttle servo lead. There are also 2 large grommets for the hole on the side of the motor box where your ignition spark plug wire will exit.

27

28

33. Install your choice of prop (if using the DA-50 we highly recommend the Falcon 23x8 Carbon Fiber prop) and Extreme Flight 4" carbon fiber spinner. We have spinners available that are painted to match these color schemes. 34. Install your switches (there are suggested switch mounting locations laser scribed in the fuselage sides visible from the interior of the fuselage), batteries and receiver. In our prototype flown with the GP-61 we mounted our batteries on either side of the fuel tank for correct balance. We used Pulse receiver batteries, 2S 2550mah for ignition and 3600mah for servos/receiver. 35. The wings are attached to the fuselage using a brand new quick mount lever system. There is a steel stud mounted in the root of the wing. The wing is slid onto the carbon fiber wing tube and against the fuselage side and the lever inside the fuselage is pushed into place, capturing the stud. This is a very secure system that allows fast assembly and disassembly of your model at the flying field.

29

36. Included with your MXS are a set of Side Force Generators (SFGs) along with 2 clear spacers to be installed between the SFGs and wing tip to prevent them from interfering with aileron movement. They are to be installed using the supplied white thumb screws threaded through the holes in the SFG, through the clear spacer and into the pre-installed blind nuts in the wing tip. 37. The canopy is attached to the fuselage using the 2 spring loaded latches in the rear of the canopy and two of our new Carbon Lock canopy latches in the middle of the canopy. Apply slight down pressure to the canopy when engaging the Carbon Lock canopy latches.

This completes the assembly of the 85" MXS. As a final step clean the entire aircraft with glass cleaner, apply your choice of graphics, then apply a coat of spray-on wax and buff the finish to a high gloss with a micro fiber cloth. My favorite product for this is Eagle One Wet Wax AS-U-DRY, available in the automotive section of most Wal-Marts, K-marts, Sears, Targets, etc. People often ask me at trade shows how I get the planes to look so shiny, this is my method.

Set-up and trimming Besides basic assembly, this is the most important part of preparing your airplane for flight. It can also be the most time consuming, but once your plane is properly dialed in you will agree it was time well spent. The range for the center of gravity begins at the rear the wing tube and extends 1" behind it. One of the best ways to fine tune the CG for your aircraft is the 45 degree line test. Fly the aircraft in front of you from left to right (or right to left if you prefer) at full throttle. Pull the aircraft into a 45 degree up line and establish this line. Roll the aircraft inverted, neutralize the elevator and pay close attention to what the plane does. Ideally the plane will continue on this line for several hundred feet before it starts to slowly level off. If the airplane immediately drops the nose and dives toward the ground it is nose heavy. If it begins to climb inverted toward the gear it is tail heavy. There is no need to have the MXS excessively tail heavy to perform 3D maneuvers.

30

Control surface throws I highly recommend that you purchase a throw meter that measures in degrees. There are several units available commercially. These units are a great aid in set-up and definitely beat the “that looks about right” method. For any type of precision flying, surfaces that travel equal distances are a must. The following control surface travels are what I use on my own MXS. These are a good starting point, but are by no means the only way to set up the MXS. Start here and then adjust to fit your own preferences and style of flying.

Elevator: 10-12 degrees low rate, 18-20% exponential all you can get for high rate, 50-60% exponential

Aileron: 18-20 degrees low rate, 30-40% exponential all you can get for high rate, 50-60% exponential

Rudder: 20 degrees low rate, 50% exponential all you can get for high rate, 60-70% exponential.

Again, this is just a starting point. Adjust to your liking. Thanks again for your purchase of the Extreme Flight RC 85" MXS ARF. I hope you enjoy assembling and flying yours as much as I have mine. See you at the flying field! Chris Hinson Extreme Flight RC